More than 500 artefacts missing from the Imperial War Museum “shouldn’t cause immediate alarm”, a Government minister has said.

Conservative MP Jane Stevenson grilled the industry and Government about the missing items during a session of the Culture, Media and Sport Committee on Wednesday, which was called in the wake of thefts at the British Museum.

She asked a Government minister: “Are you treating this as an isolated incident just affecting the British Museum.

“We have had 560 objects logged, missing, from the Imperial War Museum, for example… is this a wider issue than just one or two museums?”

Lord Parkinson, parliamentary under-secretary of state for arts and heritage, responded: “We are not treating this in isolation. We have written to our other national museums… to ask for assurances about their processes… and they are being forthcoming about items missing or unaccounted for in their collections.

“But there are a variety of reasons and explanations for that, and I think it’s important, on behalf of the sector, to stress that some of those numbers shouldn’t cause immediate alarm.”

He added that museums throughout the country are thinking about security following an estimated 2,000 items from the British Museum – including gold jewellery, semi-precious stones and glass – being missing, stolen or damaged.

Maria Balshaw, chairwoman of the National Museums’ Directors Council (NMDC) and director of the Tate art museums and galleries, said: “The Tate has not lost or had any items objects stolen from any of its stores or collections.”

She added that there are “no records” of items missing before or since she was appointed as a director.

Ms Balshaw, who has held a role as director of the Tate since June 2017, also clarified that 559 objects are currently “lost and misplaced” from the Imperial War Museum.

She added that knowing the items are lost gives her “reassurances” the body is across its record-keeping.

Ms Balshaw also claimed that the Tate “regularly audits” the collection, made up of just under 80,000 items, and all have been catalogued.

“We know where things were, and could identify if they were lost, misplaced or stolen,” she added.

The British Museum’s interim director, Sir Mark Jones, disclosed to MPs on Wednesday, during the CMS committee hearing, that one million artefacts at the London-based attraction are unregistered.

He also said there are increased security measures, including governing access to strongrooms, and some 350 missing items are in the process of being returned.

An Imperial War Museum spokesman said the lost items “date from many years or even decades ago, long before our current collections management systems were put in place”.

The statement added: “They are also typically low-value, mass-produced items – for example, 156 maps, 39 photographic negatives, 23 video tapes and 38 posters – and in most cases we still have duplicates or digitised versions.

“We take any losses very seriously, which is why we inform the police where there is a suspicion of theft, and carry out a thorough investigation for every lost item.

“These investigations have never established any evidence of internal malicious activity.

“IWM has clear systems in place to safeguard the 33.5 million items in our care. These include regular audits and spot checks, restricted access to our stores, and an audit trail of what has been accessed, when and by whom.”