Ring pulls, needles, a syringe and a turquoise ring are just some of the items that have been found in an unusual archeological dig – at Turbo Island.

The patch of land between Stokes Croft and Jamaica Street, which has been frequented by homeless people and street drinkers for decades, is being excavated as part of a project looking at homelessness.

Homeless people in the city are helping police officers, Bristol University students and English Heritage archeologists to uncover items left on the island over the years.

The three-day dig is being funded by The Council of British Archaeology and finishes today.

John Schofield, an archaeologist at English Heritage, said: "Places that matter to homeless people and those who have a marginalised existence in society are significant in their own right. This dig is a way of engaging them in an archaeological process that can be both fun and informative, while at the same time finding out more about what heritage and the past mean to the homeless.

"We have found evidence of homelessness in the form of drinking and drug taking paraphernalia such as ring pulls, needles and a syringe, which we are going to try and date because it doesn't look modern.

"We also found a turquoise imitation ring."

Smiler, 44, has just been re-housed in Dove Street after 20 years of homelessness, and has been helping the experts on the dig.

He said: "I am not sure how much homeless people will value the dig because they have a day to day existence – it's a shame but it's the way it is. But I do think it is worth doing because it teaches people how the homeless live.

"The most interesting thing I have found here today is a steri cup – an aluminium container people use to cook heroin. I was really surprised because people don't normally have them in Bristol."

PC Jen Appleford, who has taken part in the dig, said: "The police were really keen to participate in this community heritage project, it allows us to engage with the homeless, street drinkers and wider community in a fun, mud-filled day with a common goal.

The results of the dig will be presented in talks and lectures in spring 2010, culminating in an exhibition in Stokes Croft.