Alleged serial killer Stephen Port used victims from Lewisham and Gravesend as part of an elaborate cover-up on Facebook, a court has heard.

Port, 41, is on trial at the Old Bailey accused of giving four young men fatal doses of date rape drug GHB to have sex with them at his flat in Barking.

The victims include Gabriel Kovari, 22, from Lewisham, and former Dartford schoolboy Daniel Whitworth, 21, from Gravesend.

Port posed as an American student to befriend the boyfriend of Mr Kovari on Facebook, the court has heard.

Going by the name of Jon Luck, the chef had a series of exchanges on social media with Mr Kovari's Spanish partner Thierry Amodio.

He suggested Mr Kovari had been killed by Mr Whitworth, who in turn had died because he "could not live with the guilt", the court heard.

The two young men's bodies were found dumped in a graveyard 400 metres from Port's flat within three weeks of each other in 2014.

Prosecutor Jonathan Rees QC told jurors it was now accepted that a suicide note in which Mr Whitworth appeared to take the blame for Mr Kovari's death was written by Port.

In the messages to Mr Amodio, Port said he thought Mr Kovari had gone to a sex party in Barking with a man called Dan who he had chatted with on dating app Grindr.

He explained orgies happened in the area where older men tried to meet younger ones for sex, saying: "They get young guys so high they just rape them. That's why I would not go to an orgy."

Port told Mr Amodio: "He made just one mistake and it cost him his life - if he did meet his end at this orgy.

"If all he wanted was good sex he could have just come back to mine. I know he liked me."

He went on to express concern that police were going to come to his door because of messages on Mr Kovari's phone, adding: "I wish I could have warned him not to go to a sex party in this area."

He said he was "in shock" about what happened and asked if his name had been mentioned to police.

Mr Amodio asked Port to tell officers what he knew of Mr Kovari's last movements, but the defendant made a series of excuses why he had not been in contact, the court heard.

He told Mr Amodio he hoped the drug dealer involved in the deaths would be found, saying: "I hate drugs, there should be life sentences for dealers."

On how the two young men ended up dead in the same place weeks apart, he suggested: "Maybe he (Mr Whitworth) killed Gabe and couldn't live with the guilt."

Port denies 29 offences against 12 men - including four murders, seven rapes, four sex assaults and administering a substance with intent.

The trial continues.