A woman suspected of killing two of her children in the US before leaving the country has been arrested in the UK and has appeared in court in London to face extradition proceedings.

Kimberlee Singler’s nine-year-old daughter and seven-year-old son were found dead on 19 December when police responded to a report of a burglary at their home in Colorado Springs. Police later said the report turned out to be unfounded.

Singler, 35, initially cooperated with police but disappeared during the investigation, said Ira Cronin, a spokesperson for the Colorado Springs police department.

Police obtained an arrest warrant on Tuesday on charges of murder and attempted murder, among other allegations.

Singler was not under surveillance and was last seen in Colorado Springs on 23 December, said Cronin.

US authorities did not provide further details on the overseas arrest, but said they were working with multiple law enforcement agencies.

She appeared at Westminster magistrates court on Monday.

The UK’s National Crime Agency confirmed on Monday it had arrested Singler.

A spokesperson for the NCA said: “On Saturday 30 December 2023 in the Kensington area of London, officers from the National Crime Agency’s national extradition unit arrested a 35-year-old female wanted in the United States of America for offences including two counts of murder and one count of attempted murder.

“She will appear before Westminster magistrates court today [1 January] for commencement of extradition proceedings.”

When police responded to Singler’s home in Colorado they found her with minor injuries, the two children’s bodies and her 11-year-old daughter hurt. At first, Singler was treated as a burglary victim, said Cronin.

The injured girl, who was hospitalised for a few days before being released, is recovering in Colorado Springs, said Cronin.

The children’s deaths came amid a legal battle between Singler and her former husband, Kevin Wentz, over parenting time and other issues, according to US court filings. Reports have said Singler faced losing custody of her children imminently.

On Sunday, Wentz put out photos of his two children who died and their names, Elianna “Elie” Wentz and Aden.