A former finance manager for Kensington and Chelsea Council has admitted defrauding around £60,000 from the Grenfell Tower victim fund.
Jenny McDonagh took £62,000 meant for survivors of the tragedy using pre-paid credit cards.
She spent the funds on trips to Dubai and Los Angeles, expensive dinners and online gambling.
McDonagh, 39, was first arrested on August 1 and used a stolen card again two days later.
McDonagh, from Abbey Wood, south-east London, pleaded guilty to two offences of fraud, one of theft and another of concealing criminal property, at Westminster Magistrates Court on Thursday.
Prosecutor Robert Simpson described her as a “serial fraudster” who “lives beyond her means and gambles”.
He said she used the stolen funds for a “trip to Dubai, Los Angeles, meals in expensive restaurants, hair appointments and personal luxuries for herself”.
He added: “She spent quite a lot of money on online gambling.
“She spent £32,000, of which £16,000 was winnings, and lost roughly £16,000 in online gambling.”
Mr Simpson said she was also under investigation for suspected frauds against her former employers, Medway NHS Trust in Kent and the Victoria and Albert Museum in London.
“It’s suggested she obtained around £35,000 by means of fraud when working for the NHS trust,” he added.
He said the alleged fraud against the museum “hadn’t got far enough for her to obtain anything from it, but it had potential”.
McDonagh appeared in the dock wearing a large green coat and showed no emotion as the details of her offending were relayed to the court.
She was released on conditional bail with an electronic tag and will be sentenced at Isleworth Crown Court at a date to be set.
Senior District Judge Emma Arbuthnot said “custody is the obvious place to go” and ordered a pre-sentence report.
She also ordered that McDonagh quit her current job as finance officer at a mental health charity and inform the police before taking on any further work.
She also has to surrender her passport and is banned from applying for other travel documents.
Seventy-two people died as a result of the fire on June 14 last year.
A Kensington and Chelsea Council spokesman said: “We take fraud very seriously and we have always taken action to root out Grenfell fraud wherever it takes place.
“Over many months our fraud team has worked with the police to build cases and push for prosecutions against anyone who sought to take advantage of last year’s terrible tragedy.
“On this occasion it was one of our own members of staff who managed to defraud the council by getting past our own systems and processes. This is both shocking and unforgivable.
“We discovered the fraud and took action straight away, including strengthening our internal processes. We apologise to the survivors and families for any distress this may cause.”