But it is understood that he was invited by Taylor to talk to a group of people who had complaints about Serco's management, which is currently under review.
It is believed that among the group of people he spoke to were rapist Robert Roper, drug smuggler David Ikenna Obiaga, and Toka Inamata, who is in prison on robbery charges.
Among the claims former Mt Eden inmates made were that they had been severely beaten and offered bribes by guards not to lay complaints.
In one case, an inmate was allegedly beaten by another prisoner with a pool ball inside a sock.
"He has broken bones in his hand, his thumb, his nose looks like is has been shifted sideways and he says he can't breathe through his nose. It is pretty horrendous," Mr Davis said.
Another prisoner who was being held in remand at the Mt Eden prison was severely beaten by convicted inmates, who were meant to be kept in separate parts of the jail.
The prisoner alleged that after writing several letters to Corrections officials, a Serco staff member offered him a $10 phone card if he stopped laying complaints.
Some of the inmates Mr Davis spoke to had serious criminal records and were serving long sentences.
Roper was jailed for 13 years in February for abuse and rape charges. Obiaga was involved in an international drug cartel and was sentenced to 15 years for his role in importing $2.5 million of methamphetamine to New Zealand. Inamata was jailed after facing charges of aggravated robbery, threatening to kill and kidnapping. Taylor has more than 150 offences, including drugs, firearms and kidnapping offences.
Mr Davis said he strongly believed the prisoners' claims were credible.
"They are not jay-walkers," he said. "Some are facing 10 or 15 years. But they're not lying," he said.
The Labour MP was concerned that some of the assaults had been recorded by medical staff, but had not turned up in Serco's assault statistics.
Serco had to reach targets to get performance-related payments, and assaults had to be limited to 0.9 per 100 inmates.
The Corrections Department took over MECF two weeks ago following numerous reports of violence within the prison.