A murder inquiry has been launched into the "violent and horrific" death of Polish student Angelika Kluk whose body was found inside a Glasgow church.
Angelika Kluk had been working in Glasgow as a cleaner
Police said that forensic tests would continue at St Patrick's Roman Catholic church for a number of days.
Detective Superintendent David Swindle confirmed that Peter Tobin, who knew Ms Kluk, had been arrested in connection with an unrelated matter.
He said he was keeping an open mind on who was responsible for the killing.
Mr Tobin, 60, was arrested by the Metropolitan Police in London on Saturday.
Strathclyde Police confirmed that officers were due to travel to England in order to escort Mr Tobin, who had been working informally as a handyman at the church, back to Glasgow for questioning.
Mr Tobin was one of the last people to see Ms Kluk before she was reported missing last Monday.
He is being held on an unrelated matter for an outstanding warrant under Section 84 of the Sexual Offences Act 2003, a police spokeswoman said.
Cards and flowers have been left at the gates of the church
Det Supt Swindle told a media conference on Sunday that Ms Kluk had died as a result of a "horrific and very, very violent attack".
He added: "We have had great support from members of the community and we have had a good response to our enquiries."
The police officer said he was interested in hearing from people who had visited the church or the nearby presbytery last Sunday.
"We know other people were coming and going (to the church) and in an effort to piece together who murdered Angelika we would appeal to people to contact us. It may be a lengthy investigation," he said.
Det Supt Swindle said he would not be drawn on the cause of death or say whether Ms Kluk was sexually assaulted.
Open door policy
He added: "This is very, very early on in the investigation.
"What I want to lay straight is there are various lines to this investigation and we have an open mind as to who is responsible for it."
Ms Kluk was reported missing after she had failed to turn up for work as a cleaner almost a week ago.
Her body was discovered in a police search of the church on Friday evening.
It was Ms Kluk's second summer in Glasgow, having visited Scotland the previous year along with her father and older sister Aneta.
On both occasions she stayed at St Patrick's chapel house where priest Father Gerry Nugent operates an "open door policy" for those in need of shelter.