Police have found wanted criminal Rodney Clavell dead following a 13-hour siege in the Adelaide CBD.

Clavell had been on the run from police since May 22 and Police swooped on brothel on King William Street at about 1am this morning after being tipped off that he was on the premises.

South Australian Police Assistant Commissioner Paul Dickson said Clavell was found dead by police at 1:40pm after police deployed a robot into the premises.

Assistant Commissioner Dickson said the matter was being treated as a death in custody and will be referred to the coroner.

He said he understands that the siege had a significant impact on the community, but he said they believed Clavell was a serious risk to society.

In the 14 days Clavell was on the run, police had received information that he had committed several other serious offences.

One of those crimes was believed to have been an assault on a woman on May 25 in Elizabeth Park while he had a shot gun.

Assistant Commissioner Dickson said police were unable to speak to the fugitive at any time during the siege and they did not want the situation to end in Cavell’s death.

Earlier, four women were brought out of the building looking “distressed and injured”.

Assistant Commissioner Dickson said the women were extremely distressed and they would be spoken to at a later stage.

Clavell was believed to be armed with a rifle and a cache of ammunition. Mr Dickson said police had located a firearm but would not go into any more detail about how he died.

About 11am South Australian police appealed directly to the armed fugitive to give himself up peacefully in an “unprecedented” siege.

Adelaide’s CBD was locked-down for most of the day as police tried to convince Clavell to leave the the escort business called Marilyn’s Studio on King William Street.

The streets near the building have since opened to traffic.

Police feared Clavell, who was considered a dangerous criminal, would not be able to handle the escalating standoff.

“Rational decision making gets harder for Rodney as time goes on so a decision he might make now which is quite valid, in 24 hours time with no sleep might be a bit problematic,” South Australia Police Superintendent Peter Harvey told a press conference at 11am.

“So we have this avenue of clarity and an opportunity to have some good calm thinking.”

BREAKING: Fourth woman being assisted from building where #Clavell is holed up in #Adelaide. Looking distressed and injured.

— 7News Adelaide (@7NewsAdelaide) June 5, 2014

Police had appealed for Clavell, who has a history of heavy drug use, to surrender amid fears the stand-off could escalate.

Superintendent Harvey said authorities wanted to end the stand-off peacefully, and were urging Clavell to answer their phone calls and speak with negotiators who were on the scene.

Police had called for the wanted criminal to come out and speak to them.

“Rodney, we know you have concerns about your safety,” Supt Harvey said in a live television address. “We want to end this peacefully.”

From on high: #Adelaide police lock down brothel in #Clavell hunt. @theTiser pic.twitter.com/6ymhn6sZcu

— Sean Fewster (@SeanFewster) June 4, 2014

A “close associate” of Clavell has told Adelaide newspaper The Advertiser the wanted criminal was armed with a .22 rifle and had vowed to kill police if cornered.

She said Clavell had stayed at her house on Sunday night and discussed the scenario.

“He thinks they have it in for him, he will take police out,’’ she told The Advertiser. “He knows he won’t survive this alive today.”

Police earlier warned that “there won’t be people going to work in some businesses in King William St for some time”, as they appeal for patience in the siege.

The 46-year-old has been on the run for a fortnight after police issued a warrant for his arrest over breaching a firearms prohibition order.

Stress that people are avoiding using the term ‘hostages’ in relation to Clavell situation. But there are people inside. @7NewsAdelaide

— Roscoe Whalan (@RoscoeWhalan7) June 4, 2014

A former prison guard, Clavell has a long criminal history and was wanted for offences including breaching a firearms ban.

In 2004, he was shot twice by police during a chase through the Adelaide Hills when he stole a 12-tonne grader.

Four years later, he was involved in rioting at regional Port Augusta prison.

#Adelaide CBD in lockdown as police try to negotiate with wanted criminal Rodney Clavell @SkyNewsAust pic.twitter.com/L40SR0zPRN

— Stacey Lee (@Staceylee_) June 4, 2014

In 2004, Clavell used a 12-tonne grader to flee from police. He was shot twice and tasered by STAR Group officers after the 46km chase through the Adelaide Hills.

He served four years in jail.

– with ABC