Richard Williams, the father of tennis champions Venus and Serena Williams, is reportedly battling dementia after suffering two strokes.
At present, the 77-year-old is involved in a legal dispute with his former partner Lakeisha Graham relating to the transfer of his home in Florida into her name.
But according to legal documents obtained by British newspaper The Sun, Richard, who coached his daughters in their early careers, is "totally incapacitated to conduct any business".
The papers claim he suffered a series of strokes in 2016 which have left him barely able to speak or argue against Lakeisha in the case.
"The complications after the stroke included inability to remember things which happened recently and incidents that happened years ago," testimony from his doctor, Monica Williams, reads.
It also states that after the strokes, his "muscles weakened", he has "problems speaking", and suffers from "cerebral vascular disease".
Richard's lawyers claimed that Lakeisha forged his signature to change the mortgage deed on his property in Palm Beach into her name.
They claim an associate of Lakeisha's pretended to be him, so that she could borrow nearly $300,000 (£232,000) of equity on the house to start up a trucking business.
Richard is suing Lakeisha and David Simon, the lender whom she borrowed from. The lender has demanded Richard disclose any gifts or income he receives from his daughters - a request he has refused.
The former tennis coach divorced Serena and Venus' mother Oracene in 2002. He married Lakeisha in 2010 and they parted ways in 2017.
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