A mystery has been solved over the white powder which caused alarm amongst Greenwich dog owners and sparked concern the animals were being poisoned.

Dog walkers were being warned that a mystery white powder left around roads in the area could make their pets seriously ill if eaten.

Medivet in Greenwich South Street had a call from one dog owner on September 16 whose animal has been left vomiting and with diarrhoea after reportedly coming into contact with the powder.

The same surgery dealt with a spate of similar incidents last year, saying it left around six dogs ill over a two-day period.

However, Royal Parks, which runs Greenwich Park, have revealed the powder is in fact flour, left by members of a local running club to mark our their route.

According to the Greenwich Dogwatch organisation, similar sprinklings of white powder were spotted over a 24 hour period  in Ashburnam Grove, Royal Hill, Point Hill, West Grove and Greenwich South Street.

It was even reported sprinkled outside the homes of dog owners and around lamp posts.

A spokeswoman for Dogwatch said: "Just try to avoid it. If your dog shows any signs of illness, take them straight to a vet."

Head nurse at Medivet Katie Shine said she had reported the most recent incident to the police and was hoping some analysis could be done on the powder.

She said: "We've had one case already of a dog who was vomiting with diarrhoea."

Ms Shine added: "It's not just parks, it's been left outside people's houses who have go dogs as well."

The nurse said of last year's sick animals: "They were quite poorly but we were able to treat them."

However, Paul Tylor from the London Hash House Harriers told News Shopper his running club was responsible and wanted to reassure people it had only been put down to make a trail for joggers to follow. 

He said: "One thing we'll look at is how we can prevent this from occurring again."

A spokeswoman for Royal Parks said: "We are aware that a park user has been placing flour in Greenwich Park to mark out a running route.

"This is unauthorised activity and we have alerted the Metropolitan Police."