From 02 FEB 2020:
"See 5 pages about Halifax II DT620 shot down over the Baltic Sea off Stevns on 14 March 1943 mostly by Niels B. Pedersen (short name 5HALsd).
See Google Map p143 HAL DT620. Zoom. Also SDFE-map HAL DT620. See p143MACR about this crew and FLUKO - German map. Overview of the crew.               

Comment by Anders Straarup:  Masson and Ross were taken to Rødvig and then to Air Station Kastrup and Bispebjerg Cemetery, see Funeral Bispebjerg.
Smith was taken to Store Heddinge Hospital, fetched by the Wehrmacht and buried in Bispebjerg on 26 March.
Harrap was found at sea, taken to Rødvig and buried in Bispebjerg Cemetery on 7 April.
Sixsmith was found on 14 April and taken to Store Heddinge Hospital and then to Air Station Kastrup according to 5HALsd. Sixsmith was buried on 19 April.

We know that Danish Aviation Historical Review states about the 6 bodies: "Among the 6 was Air Gunner Sgt Thomas Mairs who drifted ashore at Harvig on 24 April. According to English reports his body was identified in Store Heddinge Hospital. However, Sgt Mairs is still buried as Unknown in Bispebjerg." He was buried 4 days
later on 28 April, see MAIRS.

The Canadian Virtual War Memorial has this about Sergeant Donald Robin Ross and about others buried in Bispebjerg Cemetery, including Sgt Thomas Mairs
and this - see Digital Collection Crew List 1943 * Crew List 1949 * Casualty Enquiry D.122 * Amendment to D.122 * Funeral Bispebjerg - about F/Sgt E.S. Masson
and other crew members, documents copied to AirmenDK to make them easier to read.

See Casualty Enquiry D.122 of 2 December 1946, paragraph 8: "- as according to Danish Police reports the body of Sgt. Mairs was washed ashore on the 23rd April, 1943, at Harvig, approximately one month later, taken to Store Hedding Hospital and identified by his discs, and a driving licence found on him. He was collected from there by the Germans. No burial details were made known to the Danish authorities."

The Germans must have taken care of the body of Sgt Mairs in the same way that they treated the other bodies.

See Funeral Bispebjerg - a document in German with a translation into English stating that Ross and Masson were buried with full military honours as also stated in 5HALsd. Why should the Germans then dump the body of Mairs in some unknown place? It is a fact that the Germans took a drowned airman to Bispebjerg to be
buried on 28 April 1943. However, if grave 129 contains some other perished English airman than Mairs, the Germans should have had a number of dead airmen and
then they just picked one chosen at random! SIXSMITH was buried on 19 APR 1943, and on that day the Germans ran out of deceased airmen! It must be the body
of Mairs in 129!

Halifax DT620 is p143.htm on the chronological list of 463 air crashes mentioned on AirmenDK. It is impossible for me to see which other plane crashed at sea during
the previous weeks - and then an airman not accounted for should have been taken to Bispebjerg Cemetery!
My conclusion: Based on all evidence Sergeant Thomas Mairs must be the airman buried in grave 6-129 in Bispebjerg Cemetery."

Addition 2023: On 02 FEB 2020 I sent another submission to the CWGC that Sergeant Thomas Mairs must be the airman in grave 6-129 in Bispebjerg Cemetery.
On 14 MAR 2023 - 80 years after the crash of HAL DT620 - there was a final reply from the CWGC from which I quote the first and the last parts:

"Dear Mr Staarup,
I regret to have to inform you that we are unable to accept your latest submission regarding the identification of graves at Bisperjerg Cemetery. We understand that this will come as unwelcome news but as we explained in our response to your previous submission, in order for us to re-investigate we require a clear presentation of new evidence which has not previously been considered.
- - -
We appreciate that you have made concerted efforts over many years to try to locate more information, but those searches have not provided any new records not already considered. Thank you for your dedicated attempts, but given the limits of the physical evidence cannot ever be overcome, we must now finally close the case and draw this correspondence to a close.

I know that you will join with everyone at the Commission in continuing to honour all those airmen who remain missing across Europe, including those who are buried at Bisperjerg, whoever they are. Their service and sacrifice will be commemorated in perpetuity on the Air Forces Memorial at Runnymede, so they will never be forgotten.
Kind regards Mel, Mel Donnelly, Head of Commemorations Casework, Commonwealt War Graves Commission."

My reply on 15 MAR 2023: To the CWGC, Att.: Head of Commemorations Casework Mel Donnelly,
Dear Mel Donnelly, Thank you so much for your final response to my submissions about Sergeant Thomas Mairs. Unfortunately negative, but it was worth a try.
Kind regards  Anders, Anders Baadsgaard Straarup.