Parramatta skipper Kieran Foran is taking legal action against radio station KIIS over claims he is not the father of his second child.

Foran, who is in a rehabilitation facility, and former partner Rebecca Pope recently ended a long-term relationship. Radio host Jackie O referred to rumours about the child's paternity during the Kyle and Jackie O Show last week.

McGirr Lawyers, the firm acting for Foran in his attempt to recoup about $140,000 in alleged outstanding payments from his time at Manly, have begun legal proceedings against the Australian Radio Network. Daniel McGirr has sent a concerns notice to the network, demanding an on-air apology on Friday's breakfast show.

According to the Nine Network, the letter said: "Statements were made by Jackie O suggesting our client's child is not his … This statement gave imputations that the former partner of our client committed adultery during their relationship. That imputation is defamatory, completely false, untrue, and lacking any merit.

"We are instructed to request that you submit a clear apology and retraction to Mr Kieran Foran and Ms Rebecca Pope."

KIIS said in a statement released on Thursday night they had not received any correspondence from Foran's lawyers, but apologised for any hurt caused.

"It has been reported ... that legal action has been taken against KIIS 1065 regarding comments made on air," the statement said. "As of 9pm today KIIS 1065 has not sighted any legal letter.

"Jackie and the KIIS team are mortified that anything said has caused hurt to Kieran Foran and his family at such a difficult time. We apologise unreservedly for this and wish them all the best."

Foran was rushed to hospital in an ambulance last week after overdosing on prescription medication. He missed Parramatta's win against Canterbury and won't feature in the New Zealand side taking on Australia, instead focusing on his health.

The Eels have granted Foran an indefinite leave of absence.