The pair dated for several months after being introduced late last year, but Andre confirmed that he had split from the Spanish model in April.
Attending Childs's 21st celebration in London, the Daily Star claims that the two appeared unwilling to appear together when arriving at the Soho venue. However, inside the pair apparently surprised other guests by kissing each other.
"They certainly looked like a couple again," a source told the paper. "In fact the word that evening was that they're back as boyfriend and girlfriend.
"They looked in great spirits and completely loved up. There is clearly chemistry still there. The snogs they were having looked quite steamy."
The insider added: "Everyone was saying they must be an item again."
A spokeswoman for Andre commented: "Peter and Elen are still friends and enjoy spending time together."
Rivas's ex-fiancé Frank Lampard - with whom she had two children - yesterday announced that he is engaged to Daybreak presenter Christine Bleakley.