EXCLUSIVE: How wealthy businesswoman Melissa Caddick's WhatsApp account has mysteriously been accessed 'at least twice' since she vanished - as police investigate whether her disappearance has been staged

The Whatsapp account of a missing Sydney businesswoman has mysteriously been accessed at least twice since she disappeared from her $7million cliffside mansion. 

Mother-of-one Ms Caddick, 49, hasn't been seen since she disappeared from her Dover Heights home about 5.30am on November 12 - a fortnight ago. 

A friend of Ms Caddick's has revealed her WhatsApp account linked to her phone number updated to say it had been 'last seen' at 1.44pm on Tuesday this week.

Before that, a 'last seen' alert popped up on the previous Thursday, at 10.02pm, according to screenshots supplied to Daily Mail Australia. 

The NSW Police Force did not directly respond to questions about whether investigators or another party had accessed Ms Caddick's WhatsApp account.

Instead, a police spokeswoman urged anyone with information about her whereabouts to come forward.  

Melissa Caddick vanished from the home she shared in Dover Heights with her husband Anthony Koletti . Above, at a wedding together

Mysteriously, Ms Caddick's account has popped up at least twice on Whatsapp, according to contacts of hers, who noted alerts have popped up saying she was 'last seen' on the app on two recent occasions

'As the investigation remains ongoing, there are no further updates at this time,' she said. 

The official likewise didn't respond to questions about whether her mobile phone is in the custody of police. 

But WhatsApp chats do not necessarily require a mobile phone to be used - as they can be accessed via a computer if an account is synced up. Bondi detectives are aware of the developments. 

It has been revealed that police are investigating a theory that Ms Caddick may have staged her disappearance, although that is believed to be just one of several scenarios being probed by detectives since she vanished two weeks ago. 

EXPLAINED: WHATSAPP 'LAST SEEN' FEATURE

Another sighting of her WhatsApp account was at 1.44pm this week

The messaging app's 'last seen' feature 'refers to the last time the contact used WhatsApp', its official website said. 

Users can control whether their 'last seen' can be seen by members of the public, just by their contacts, or not at all.

Ms Caddick's WhatsApp appears to have been set to broadcast her 'last seen' to her contacts only.  

The app can also be accessed through alternative means, via a desktop computer, if an account is synced up.

Users can chat online through a web browser or a downloaded app, the official WhatsApp website said.  

The businesswoman was dressed in her activewear when she left the house about 5.30am on Thursday, November 12.

She was apparently headed off on her usual morning run but left her phone and keys at home.  

Security camera footage of the front of her house the home did not capture the events of that morning, frustrating standard police checks. 

Two days earlier, the businesswoman had been raided by the Federal Police in connection with an investigation by the corporate regulator, ASIC.

She was also slapped with a Federal Court order, ordering that her passport be surrendered and barring her from selling, disposing of or mortgaging her assets. 

A hearing in Ms Caddick's case will come before a Federal Court judge tomorrow, where further details of the case are expected to come to light. 

A week ago, her husband, Anthony Koletti, 38, made a public appeal for his wife to return home, alongside a detective and Ms Caddick's brother, Adam Grimley. 

'You know how much we love you. Just come home. Everything's taken care of. You're not in trouble,' said Mr Koletti, a DJ, hairdresser and car enthusiast.

Mr Koletti said he had last spoken to his wife the night before she disappeared and she was 'normal'.  

He was asleep when she left the house but her son is understood to have been in the home's gym at the time, and heard the front door shut as she left. 

The pair later found Ms Caddick's belongings at home and began to suspect something was wrong. 

Mr Koletti said Ms Caddick regularly went for a run and 'always took her phone - in this case it is the only time since I've known her that she did not take her phone with her'. 

Where is she? Mystery surrounds the location of the Sydney businesswoman - who was under pressure due to an ASIC investigation

Her husband Anthony Koletti and brother Adam Grimley fronted a public appeal this week. Mr Koletti told his wife 'just come home ... you're not in trouble'

Mr Koletti reported his wife missing the following day. There is no suggestion that he or Ms Caddick's brother played any role in her disappearance. 

Bondi Police acting crime manager Stuart Thomas told The Daily Telegraph on Thursday that investigators were keeping an open mind.

'It's been two weeks now and we are very worried for her welfare,' Mr Thomas was quoted saying. 

'We are not ruling anything out at this stage and are working on several theories.

'Finding her is the priority, the family have been very cooperative and are putting on a brave face.'  

The investigation continues.  

Melissa Caddick: Timeline of Sydney woman's disappearance 

November 10: Federal Police raid Melissa Caddick's Dover Heights home in connection with an investigation by corporate regulator, ASIC.

Ms Caddick is also hit with a Federal Court order demanding she surrender her passport and restricting her assets.

November 12: Ms Caddick leaves her home in her activewear about 5.30am, with her son hearing the door close behind her. 

Her family find she has left her keys and phone at home.

November 13: Ms Caddick's husband Anthony Koletti contacts NSW Police and reports her missing. 

Detectives are seen at the home and police launch an extensive search of the area.

November 17: NSW Police issue appeal for help from the public in finding Ms Caddick 

November 19: Mr Koletti and Ms Caddick's brother, Adam Grimley, urge Ms Caddick to come home, her husband saying 'you're not in trouble'

November 25: Media report police are investigating - among several theories - that she may have staged her own disappearance

November 26: Daily Mail Australia reveals her WhatsApp accounts have been accessed since her disappearance, according to its 'last seen' feature

November 27: The Federal Court will hold a hearing in Ms Caddick's Federal Court case