A team of detectives won an award after bringing down gang members involved in the theft of a £3.5m tiara.

Nottinghamshire Police began a major investigation after the carefully planned raid at the Harley Gallery on the Welbeck Estate in November 2018.

A matching brooch was also stolen alongside the Portland Tiara, which was made for the Duchess of Portland to wear at the coronation of Edward VII and Queen Alexandra in 1902.

The audacious break-in was later linked to a series of violent robberies, including at the homes of two international footballers.

Following a lengthy investigation spanning more than two years, six men were found guilty of a variety of offences, including conspiracy to commit burglary, converting criminal property, and robbery. They were jailed for more than 100 years.

The team of detectives whose tenacity led to the convictions were recognised at Nottinghamshire Police’s annual Force Awards. They were nominated for the Investigation of the Year Award by their inspector, Gayle Hart, who delayed her retirement to see the case through.

“The team devoted countless hours to what became one of the most complex investigations I’d ever known,” she said.

“As a result of their dedication and determination to get justice for the victims, ruthless criminals were taking off the streets for a very long time.

“They should all feel very proud at what they achieved in this case.”

The team included Det Sgt Rick Ellis, Det Con Stuart Kirkham, Det Con John Wilson, Det Sgt Simon Blinston and analyst Sally Marshall.

They linked the raid to a series of subsequent robberies and burglary in early 2019 when they raided a shop in London’s Hatton Garden.

Inside police found a plastic bag containing jewellery and an FA Cup runners-up medal stolen the day before from the home of a professional footballer.

Det Con Kirkham said he and his colleagues were pleased their efforts had been recognised at this year’s Force Awards ceremony.