The London Olympic legacy has been called into question after research found around 50,000 fewer people are playing sport every week in Suffolk and Essex than in the year following the landmark 2012 Games.

According to the latest Sport England research, regarded as the most comprehensive indicator of sports participation, the proportion of people aged 16 and over in Suffolk participating in at least 30 minutes of sport at least once a week fell from 34.8% in October 2012 to October 2013 to 32.6% in April 2014 to March 2015.

It means that since London 2012, which promised to ‘inspire a generation’, the number of people playing sport every week in the county has approximately fallen from 254,000 to 238,000.

The figure for 2014/15, released by Sport England in a mid-year update for their next Active People survey, to be released in December, was the second-worst rate since the first survey a decade ago – 32.2% in October 2005 to October 2006.

In Essex, the figure for April 2014 to March 2015 (34.5%) was the lowest it has ever been. It stood at 36.8% from October 2012 to October 2013.

It follows a three-year gradual decline and means that the number of adults playing sport weekly has fallen from 514,000 in the year after the London Olympics to 480,000.

In England, the figure dropped from 19.4million to 18.8m.

Earlier this month, Dame Tessa Jowell said the chance to build an Olympic legacy of wider participation in sport has been “squandered”. She said cuts to school sports programmes had left grass-roots participation “back where we started in 2002”.

Last month, Boris Johnson said all major venues had been or were set to be opened to the public and the private investment in London which followed the Games had ensured “a phenomenal legacy”.

Tony Goldson, cabinet member for health at Suffolk County Council, said: “Naturally we are disappointed with the figures, but we are committed to increasing participation in physical activity.

“Sport plays an important part in this and are working hard with our partners to attract events like the Women’s Tour, Tour of Britain and Great East Swim, develop opportunities like parkrun, Fit Villages, the Halesworth Campus and Get Healthy Get into Sport and implement campaigns like the Suffolk Year of Cycling

“By doing so, we are confident that over time we can reverse these national trends locally.”

Last month, the EADT reported how parkrun, a free weekly 5k challenge, broke the 1,000 participant barrier in Suffolk.

A Suffolk Sport spokesman said: “Suffolk’s figure for the wider measure of three times per week participation in sport and active recreation is the highest in the East of England at 24.4%, and has shown the largest growth since the first Active People Survey.”

Meanwhile, summer deals offered by Ipswich Borough Council (IBC) include sports from 50p a day for schoolchildren and eight weeks of sport for adults for £38.

Bryony Rudkin, IBC’s leisure portfolio-holder, said: “We want to encourage young children to take up or renew an interest in sport. That is why we are offering something for everyone.”

Warren Smyth, chief executive of Abbeycroft Leisure, run in partnership with St Edmundsbury Borough Council, said its leisure centre attendances rose by 2% last year. He added: “We have also seen an increase in mass participation events such as the Women on Wheels event in Bury St Edmunds, inspired by The Women’s Tour, which saw participants double from last year, many of whom were not regularly cycling before.”

Ray Gooding, cabinet member for sport and physical activity at Essex County Council, said: “We are committed to encouraging and inspiring people of all ages to lead healthy and active lifestyles by providing opportunities for them to get involved in sport and other physical activity.

“One good example is the massive success of parkrun. More than 1,500 people a week are currently taking part in runs across the county,

“The Schools Games programme has engaged thousands of young people across the 14 districts and school sport partnerships within the county. This year Active Essex also staged the first ever Essex Special School Games, which saw about 300 schoolchildren with disabilities coming together to celebrate and participate in sporting competition.”

But Colchester bucked the national trend. The number of adults playing sport every week rose from 35.2% in October 2012 to October 2013 to 38.1% in April 2014 to March 2015 – from 36,750 to 39,750.

Annie Feltham, portfolio holder for communities and leisure at Colchester Borough Council, said the research “reflects our investment”.

She added: “As well as providing pay-as-you-go and membership at our four Leisure World sites, we have secured additional facilities for the community through a long-term agreement with Colchester Garrison.

“We have set up the volunteer-led, free Colchester Castle parkrun, now celebrating its second year and welcoming around 185 participants each week, and support both the annual Colchester Half Marathon and Cancer UK’s Race for Life event in Castle Park for 2,000 participants.”