Irish police said they received a report that Kyran Durnin was last seen in Drogheda, Co Louth, on 30 August.

Officers said he is presumed dead, with local media reporting he may have been missing for months. State broadcaster RTE said police believe he may have been killed more than two years ago.

"Despite extensive inquiries carried out to date, we have been unable to either locate Kyran, identify any information on his current whereabouts or any evidence that he is currently alive," Irish police said in a statement.

"Following inquiries to date, investigating police now believe that Kyran is missing, presumed dead.

"A murder investigation has been commenced."

No arrests have been made.

Ireland's Child and Family Agency, Tulsa, is working closely with officers.

Police in Drogheda appealed for anyone with information to get in touch.

Read more from Sky News:
End-of-life care must be fixed before assisted dying legislation - charities
'There is nothing': Farmers in Sudan on verge of mass starvation
XEC COVID variant - what is it and how dangerous is it?

"Any information, no matter how insignificant it may seem, will be welcomed by the investigation team. This information will be treated in the strictest confidence," a spokeswoman said.