Police appealing for information to trace missing 18-year-old Patrick Halpin have found a body.
A police spokesperson said it was too soon to positively identify the body.
The body was discovered at around 7.50pm today in an enclosed area in the vicinity of Burger King and the Zoo Bar off Leicester Square, W1.
Enquiries are underway to establish the identity of the deceased.
Investigating officers have cordoned off two areas in the city.
One of the areas which was sealed off from members of the public is close to the Zoo Bar, Bear St, where Patrick had been with friends.
Three police were at the scene last night, which is at the back of Bear Street.
The location is just off Charing Cross Road which runs parallel to Leicester Square, one of the busiest area areas of London.
The family of Irish teenager Patrick Halpin began a search for him yesterday, when it emerged that he did not return from a night out on Tuesday night.
The 18 year-old's sister and parents had been led to believe this afternoon that Patrick had been found at Gatwick Airport.
But they were dealt devastating news an hour later that he is in fact, still missing.
Patrick's name had been included on a block booking for a flight from Gatwick airport, and because of this it was believed that Patirck had checked in at the airport.
However, when police went to search the plane for Patrick, they realised that he was not there. The family had already been informed that he'd been found.
Regina Ní hAilpín (22), Patrick's sister, said this evening: "Hi everyone, unfortunately there was a mix-up with information, Patrick is still missing."
She urged the public to "please continue to share and retweet his picture, and keep him in your prayers".
Regina is in London with her father Paddy, searching for her brother. Patrick went missing on Tuesday night.
Regina told independent.ie tonight: "It's noone's fault. It's because his flight was on a block booking with [Dublin City University] that there was a false communication."
"The airport thought that he'd checked in and there was a phone call made to the police, and they went on to get him, only to find that he wasn't there."
"It's cruel. You're on cloud nine and now you're in hell."
The DCU student - who is originally from Loughrea in Galway - was last seen in The Zoo nightclub just off Leicester Square.
Regina and Paddy will search the area tonight, and they're appealing for the public's help.
"There is a premiere on in Leicester Square so hopefully we can get out there and ask everyone. We're back to square one. We need to up the ante now."
It's understood Patrick left the nightclub to go to a nearby Burger King.
Metropolitan Police are now trawling through CCTV footage and they placed a tracker on his mobile phone.
Patrick was visiting London with Dublin City University's drama club to see some shows in the West End.
His friends have been contacting hospitals, police stations and the nightclub in their search for him.
Patrick is studying to be an actuary in DCU, and he is part of the Loughrea Youth Theatre.
Geraldine Gittens and Shane Phelan