Around £200,000 in sponsorship is still believed to be owed to Cancer Research UK from a charity event near Norwich.

Back in May, more than 5,000 people took part in the Norwich Race for Life and Pretty Muddy challenge to support Cancer Research.

But two months on and organisers claim that just over half of the expected sponsorship income has been received.

And they are now urging those who took part to pay in the money they raised for the event.

Rachel Parratt, Cancer Research UK's Norwich event manager, said last year's race brought in £468,311 for the charity.

She added that she would normally expect the total amount to be handed in around three-and-a-half months after the event.

But so far for 2017, just £202,284 has been paid to the charity.

'Many people don't realise that their entry fee only covers the cost of the event,' she said.

'It's the sponsorship money that really makes a difference. Money raised, whether it's £10 or £100, will help Cancer Research UK scientists find new ways to treat cancer and save more lives.'

She added that it was becoming 'more common' for people to forget to hand back their sponsorship as their lives become more busy.

The unofficial statistic, she said, is that around one third of people will not donate the money they raised.

This year's 5km Race for Life event took place at the Norfolk Showground on May 14.

It was open to women of all ages, and boys aged six to 12.

Meanwhile, the Pretty Muddy 5km obstacle course was held on May 13, also at the showground.

Rachael Donovan, from Norwich, was one of those who took part in the event.

The mother-of-one has been through treatment for Non Hodgkin's Lymphoma and since getting the all clear has become a committed fundraiser for the local Race for Life and for Cancer Research UK.

She was given the chance to go behind the scenes at the Cancer Research UK Cambridge Institute to see how the fundraising is spent.

'It was such an eye-opener seeing the labs and all of the equipment. The scientists are working away every day to find the next breakthrough and we all forget they are there doing it.'

For information on returning sponsorship, visit www.raceforlife.org