Egypt is renewing its demands that the London auction house Christie’s delay a controversial sale of a statue of Tutankhamun, fearing it was looted from a Luxor temple.

The brown quartzite statue of Tutankhamun with the face of the ancient god Amun is expected to raise more than £4m at auction at Christie’s on Thursday, a day after other Egyptian artefacts were auctioned from the same lot.

Egypt’s ambassador to the UK, Tarek Adel, called for Christie’s to delay the auction, arguing that further investigation was needed “regarding the legality of trading in these items, the authenticity of their documents, and evidence of its legal exportation from Egypt”.

The Egyptian embassy said it had requested documents last month from Christie’s to show the object’s provenance. The auction house, it said, replied to confirm it had the documents, but provided no proof and did not show any documentation to the embassy.

Egyptian officials raised the alarm after the listing was made public, concerned that the 28.5cm-high statue was removed from the Karnak temple in Luxor. The statue “looks like it came from Karnak”, said Zahi Hawass, Egypt’s former minister of antiquities.

It shows the young pharaoh Tutankhamun with the facial features of Amun, “a device used to align the ruling ing with deities”, according to Christie’s description.

The listing adds that the statue was acquired as part of a lot from the Munich-based dealer Heinz Herzer. Last December, Italy’s leading court ordered the Getty Museum in California to return an ancient Greek statue by the sculptor Lysippos to Italy, after the museum paid Herzer almost $4m for it in 1977.

“It is hugely important to establish recent ownership and legal right to sell which we have clearly done. We would not offer for sale any object where there was concern over ownership or export,” Christie’s told the Guardian when contacted to comment on the original listing.

The auction house later confirmed sale on 4 July would go ahead and said they they had been in touch with both the embassy and the Egyptian ministry of antiquities about the sale.

“We have provided extensive information about the Amun Head including our full cataloguing. We have also invited them to meet with us to review the work and discuss the provenance and accompanying documentation. They have not yet taken us up on this offer but we remain happy to welcome them to discuss this object and our processes,” Christie’s said.

Adel disagreed. “The sale of such precious Egyptian artefacts is a huge shame and reflects a deep lack of respect to our efforts to stop this happening,” said Adel. He added that the auction house was ignoring “moral and ethical considerations related to the preservation and protection of cultural rights and properties worldwide”.

• This article was amended on 12 July 2019. An earlier version stated that the Getty Museum was forced to return an ancient Greek statue to Italy. In fact, it was ordered to return the statue, but says it will continue to defend its right to it.

