Johannesburg - Forensic experts will comb Radovan Krejcir's cell at Zonderwater prison on Monday, after the Czech fugitive's fourth alleged escape attempt.
"We knew that he had means of communicating, but we were always struggling to figure out how," national police spokesperson Solomon Makgale said.
"We have confiscated a number of cellphones before, now we figured out where he was hiding the cellphones."
Krejcir was moved and spent his second night in a new cell.
Makgale said every time warders raided Krejcir's cell they found cellphones.
"Then we would think 'now we have all of them'. Meanwhile there were others."
On Sunday, the Department of Correctional Services said Krejcir was allegedly planning a prison break.
The gun that was found was taken for ballistic testing and the four cellphones were being analysed.
today forensic experts will comb #Krejcir cell. He spent 2nd night in new cell. Gun taken 4 ballistic testing & 4 cellphones being analysed— Soli_M (@Solomon_Makgale) September 28, 2015
However, Makgale said police and correctional services have always been "on top of the game" and kept Krejcir behind bars.
"We knew when there were men sent from the Czech Republic last year who were going to try and kill the investigators and get him out of the country.
"He tried to insist on going to see a particular dentist at a specific time and he's tried to bribe the team that escorts him and he hasn't been successful," Makgale said.
Makgale denied claims made by forensic investigator Paul O'Sullivan that he tipped police off about Krejcir's escape plan.
According to Eyewitness News, O'Sullivan contacted police after learning that Krejcir was planning to kill him once he was out of jail.
"We’re not working with Paul. We have never worked with him," Makgale said.
"In fact, the only time the investigating officer met him was when we saved his life. We picked up that they were planning to kill him."
Krejcir, who had been charged with a number of crimes, had been behind bars since November 2012.
Earlier this month, the first conviction against him was obtained. He was found guilty of attempted murder and kidnapping of Bheki Lukhele, and dealing in drugs. Lukhele was kidnapped and tortured after his brother allegedly disappeared with 25kg of tik he had been recruited to smuggle through OR Tambo International Airport, where he worked for a cargo company.
On October 16, Krejcir was expected to hear whether he would be granted bail in a case in which he and four others were charged with the murder of drug trafficker Sam Issa. He was shot dead at an intersection in Bedfordview, Johannesburg, in October 2013.
On the same day the Palm Ridge Magistrate's Court was expected to hear another case against Krejcir and several others. This involved the murder last year of debt collector Phumlani Ncube, and the attempted murders of Colonel Nkosana Ximba and investigator Paul O’Sullivan. Both of them had been investigating Krejcir.