Carl Sargeant, a Welsh politician who resigned from his post in the Welsh Government last week after allegations of sexual misconduct, has died suddenly, British authorities say.
Labour Leader Jeremy Corbyn told the BBC he was "shocked and horrified" by Mr Sargeant's death.
Sargeant had been a member of the Welsh Assembly since 2003.
Elin Jones, assembly presiding officer, said Mr Sargeant "served the people of Alyn and Deeside with pride and determination and he made an enormous contribution to the development of this democratic institution".
Carl Sargeant had lost his ministerial job as cabinet secretary for communities and children last week.
Last week, after his resignation, Sargeant said he wanted to clear his name through an independent process.
A spokesman for North Wales Police said it was investigating an incident at an address in Connah's Quay, Flintshire. His next of kin have been informed and police are supporting the family.
Police said his death was not being treated as suspicious and had been referred to the coroner, a statement often used when a suicide has occurred. He said he did not know what the allegations against him were, but that he would step down while the investigation took place.
He said that "given the nature of the allegations", he agreed with the First Minister that he was right he "stands aside" from cabinet.
"Carl was a much loved husband, father and friend. We loved him so very much", the statement said.
He added: "I look forward to returning to Government once my name has been cleared". "The family request that their privacy is respected at this sad time". "My thoughts and profound sympathy are with his family and friends", he added.
Carwyn Jones said he was "shocked and deeply saddened."