Drones delivering weapons to two of England’s highest-security prisons have become a national security risk, the prisons watchdog has warned.

The Chief Inspector of Prisons, Charlie Taylor, said that drops of contraband to inmates at the top-security jails HMP Manchester and HMP Long Lartin in Worcestershire were now so frequent that guns could be smuggled in.

The two jails house some of the most dangerous men in the country, including terrorists, murderers, and organised crime gang bosses. Mr Taylor claimed that prison authorities had “ceded the airspace” over the jails, leading to an increasing risk of armed violence, escapes, and hostage-takings.

Mr Taylor’s warnings come in damning reports on the conditions at the maximum-security prisons. His inspection teams uncovered serious and repeated failings in security and safety, with clear evidence of gangs arranging deliveries of weapons, drugs, and phones via drones.

“This is a threat to national security,” Mr Taylor said.

“The potential for serious weapons to get into our prisons in increasing numbers means there is a significant risk, particularly in these Category A prisons, which house some of the riskiest men in the country—either connected to organised crime gangs or involved in terrorism.

“The potential for them to commit serious offences within prison, escape, or cause a hostage situation is an enormous concern.”

Speaking to the BBC, Mr Taylor revealed that gangs were now using drones capable of carrying payloads of up to 3 pounds (1.3 kg) of contraband into prisons.

Inmates have reportedly organised the delivery of “zombie knives,” and there is a real possibility that firearms could follow.

“Knives are indeed getting in,” he said. “It’s entirely possible that if someone were determined enough, they could get a gun in.”

“If a weapon gets into a prison, a prisoner could use it to take hostages or threaten staff to get closer to the gates. There’s even the possibility that someone could be picked up by a drone.“While unlikely, this is something the prison service, police, and security services must address immediately.

“In effect, the airspace above our prisons, which house some of the riskiest individuals in the country, is being ceded to organised crime gangs.”

The reports revealed that at both Manchester and Long Lartin, there were failures in CCTV systems and anti-drone netting. Officers at Manchester regularly saw drones circling the jail at night.

Inmates have also been breaking £5,000 cell windows faster than they can be repaired, using GPS apps on smuggled phones to guide deliveries to precise locations.

At Long Lartin, which holds men convicted of terrorism offences, gangs drop contraband from drones in black plastic bags. These bags are indistinguishable from those of human waste thrown out of cell windows, allowing inmates to retrieve them easily during litter patrols.

Some gangs have also hidden contraband in balls of grass to camouflage items if they land on lawns.

The prisons watchdog issued an urgent notification about conditions at Manchester in October, calling it one of the most violent jails in the country. This made it the fifth prison in a year to require an emergency response from ministers.

The Ministry of Justice said it had already acted on the notification by improving security, including installing a new CCTV system and anti-drone netting.

“This Government inherited prisons in crisis,” said a spokesman.

“We are addressing the situation by investing in prison maintenance and security, working with the police and other agencies to tackle serious organised crime, and building more prison places to lock up dangerous criminals.”