Taylor Schilling was serenaded by her castmates at her 30th birthday party at the weekend

And Taylor was particularly thrilled to see Madeline Brewer - who was killed off on the last series of the Netflix drama - arrive unexpectedly at the bash.

A source told the New York Post newspaper's Page Six column: "Taylor screamed when she saw Madeline walk in. They shared a big hug."

Taylor recently admitted she found it "terrifying" visiting a prison as part of her research into playing Piper Chapman on the show.

She said: "I did visit a prison, going into the second season. It was terrifying, sad, and really moved me.

"I was at the women's camp at Rikers Island in New York and what struck me was that so many of them were so young, in their early twenties, but everyone had children and they were overwrought about what was happening to their kids."