Such complaints to train operators increased to account for 6.9 per cent of all grievances this summer, the Office of Rail Road (ORR) regulator revealed today.
The figure went up by 5.5 percentage points between July and September compared to the same period last year.
It came in stark contrast to an overall 69.3 per cent reduction in complaints.
The ORR said: “Complaints about personal security on board the train accounted for 6.9 per cent of all complaints closed.
"This is the highest since the time series started in 2013-14 and is likely due to complaints related to Covid-19, such as the use of face masks on board the train.”
The figures also showed fewer people complained about overcrowding, which was down by 5.6 points to 1.2 per cent of the total.
Tickets and refund policies attracted the most complaints, accounting for 13.6 per cent.
Delay compensation claims resolved between last July and October went down by 89.8 per cent from 1.4 million to 145,158 compared to the previous year.
Complaints about punctuality and reliability fell to 11.6 per cent of all complaints made, down 13.2 percentage points on last year.
A British Transport Police spokesperson said: “Throughout the pandemic, our officers have conducted high-visibility patrols to support rail staff and passengers, ensuring those using the railway are kept safe.
"Passengers are encouraged to report anything suspicious by speaking to a police officer or member of rail staff, or by texting us discreetly on 61016. In an emergency, call 999.
“Wearing a face covering whilst travelling has become a part of our everyday routine and compliance with this law has been high across the rail network.
"However, a small percentage of people are failing to comply with the requirement and we therefore continue to deploy officers across the network to ensure compliance rates remain high on-board trains and in stations.
"Anyone who fails to comply without an exemption will be removed from the network and can expect to receive a fixed penalty notice.”