Sir Tim is said to be expecting his fourth child with 34-year-old playwright Laura Jane Foley, and she is due to give birth imminently, according to the MailOnline.com.

Laura Jane has been dropping hints about her pregnancy on Twitter.com, with the most recent being on 6 April (16), when she shared a photo of herself, with actor Christopher Biggins cradling her baby bump.

Sir Tim, who is allegedly worth $240 million (£150 million) thanks to his co-writing credits on hit musicals including Evita, Jesus Christ Superstar and The Lion King, has two grown up children with his estranged wife of 41 years, Jane MCIntosh, and a daughter from a relationship with Nell Sully.

His marriage to Jane broke down in the late 1980s after it was revealed he was having an affair with Chess musical star Elaine Paige. The pair split, although Sir Tim and Jane never filed for divorce.