The public inquiry into the Grenfell Tower disaster could resume in virtual form with evidence taken by Zoom videolink, its senior legal adviser has told bereaved people and survivors.

An online system has been successfully tested by role-playing barristers, and hearings could be restarted within weeks if the option is chosen following a consultation launched on Monday.

However, Caroline Featherstone, the solicitor to the inquiry, warned that “much of the solemnity” of the investigation into 72 deaths following the June 2017 fire could be lost in online hearings, and added that witnesses might even cheat with answers fed to them by unseen advisers.

The inquiry is asking participants for views on other options, which include whether it should wait for an unknown amount of time until it can resume in its original form with around 100 people, including the public and survivors, gathered in one room.

A third option of running a skeleton inquiry, with only key people attending and observing social distancing rules, is also on the table. This would not be possible until the inquiry chairman, Sir Martin Moore-Bick, 73, is allowed out of the shielded lockdown which currently applies to people over 70.

The inquiry was suspended on 16 March, ahead of the national physical distancing measures, when it was cross-examining executives from construction companies involved in the disastrous refurbishment that fuelled the fire.

Moore-Bick is keen to restart proceedings, and Featherstone said that to wait for normality to return risks a delay of months and possibly longer, which is “not in the public interest” as the work of the inquiry is “an urgent matter of public safety”.

In a letter sent on Monday, she told hundreds of core participants that the Zoom system “worked well enough to be able to obtain the evidence required without loss of audio-visual quality, undue interruption or compromising participation”.

She said the technology was approved as safe by the government in consultation with the National Cyber Security Centre and concluded: “There is little doubt that the system provides a functionally feasible way of obtaining the oral evidence required.”

But she said that giving evidence from home while under lockdown may be “traumatic” for witnesses, some of whom might not consider home a relaxed location, but rather “a place of domestic tension”. And she said there would be no immediate access to an NHS counsellor, which might undermine the inquiry’s duty of care to witnesses.

And in a consideration that will be familiar to people working from home under lockdown, she added: “It may be difficult for witnesses to keep pets, children and other distractions out of the room”.

Featherstone said the inquiry’s view was that only witnesses who are willing to give evidence remotely should do so.

Some survivors are understood to be concerned that witnesses who are due to be heard, including politicians and officials at the Royal Borough of Kensington and Chelsea and its tenants management organisation, would feel less scrutinised giving evidence remotely. Featherstone said they “may not feel the same pressure to be candid” and it was difficult to prevent them being “fed answers”.

“There is, for example, no reliable way of knowing whether a third party is prompting a witness by mobile phone or email to which the witness has ready access,” she said.

The option to restart only when the inquiry could be conducted as it was before Covid-19 would “allow the dignity and solemnity of hearings to be maintained”, but would mean a long delay. The hybrid option, relying as it does on Moore-Bick being allowed out of isolation, “is likely to involve a delay of some months, possibly many months,” Featherstone said.

She concluded “there is no easy solution” and asked for responses by next Monday.