Police have arrested a gay-rights activist reportedly yelling "they are the virus" to a Christian group running an emergency coronavirus hospital in New York's Central Park.

Wearing a bright pink suit and bandana, William Talen, 69, allegedly planted a rainbow flag into the prohibited area and shouted "they have no business being in New York City" on Sunday afternoon.

Six police officers led him and his flag away from the hospital, with the NYPD confirming in a statement on Monday that Talen was charged with resisting arrest, obstructing governmental administration, criminal trespass and disorderly conduct.

"He was instructed to leave the area, he refused, proceeded to plant a flag on a pole into the ground," the NYPD statement said.

Talen, also known by his stage name Reverend Billy and the Stop Shopping Choir, has been arrested more than 50 times for protesting against companies like JPMorgan Chase, Disney and Starbucks, according to a 2015 profile of him. Talen did not immediately respond to a request for comment.

A Samaritan's Purse spokeswoman told The Independent that their "focus remains on providing the highest level of care to all patients being treated at our Emergency Field Hospital in Central Park."

In cooperation with the Federal Emergency Management Agency (FEMA), the evangelical Christian organisation opened the 68-bed hospital as a specially designed respiratory care unit on 28 March. They opened a similar hospital in Cremona, Italy, a week earlier.

The humanitarian organisation, run by Franklin Graham, son of the Rev Billy Graham, has been criticised for having anti-LGBT views.

At a conference hosted by the Family Research Council in 2014, Mr Graham reportedly said he's "not afraid of homosexuals." On the contrary, he said, "I love them" – "I love them enough to care to warn them that if they want to continue living like this, it's the flames of hell for you."

In a statement to The Independent, a spokeswoman said Samaritan's Purse treats everyone the same.

"Samaritan's Purse does not discriminate in who we help, and we have a decades-long track record that confirms just that. We do not make distinctions about an individual's religion, race, sexual orientation, or economic status," the statement said. "Our doors at the Emergency Field Hospital in the East Meadow are going to be open to all New Yorkers who need our help. We are here to save life, which is precious in God's sight – and we do it all in Jesus' Name."

Last week, New York City Mayor Bill de Blasio called the views of Samaritan's Purse "troubling" and that his administration would monitor the situation to ensure there is no discrimination.

"I'm very concerned to make sure this is done right, but if this is done right, we need all the help we can get," de Blasio said at a press conference at the US tennis centre in Queens, where another field hospital was being built to provide relief for the besieged Elmhurst Hospital.