On 13 March 1700 the fortress Dünamünde surrendered after a Saxon assault during the night between the 11th and 12th had ended in a spectacular failure. According to Kungl. Fortifikationens historia 3:2 Charles XII on 19 April ordered Dahlbergh to investigate the circumstances surrounding Col. Budberg's decision to hand over the fortress. Munthe further states that the King countermanded this order on 26 November.
Munthe's statements are not entirely accurate. What the King did on 26 November was to permit Dahlbergh to postpone the inquest until Governor Frölich returned from a visit to the headquarters and some officers from the garrison were back in Riga.
The inquest does in fact appear to have gone on for some time. In a letter to Charles XII on 24 August 1701 the prosecutor Ingel Biörndahl notes that he had reminded the King about this issue on 25 March. Charles had replied that the inquest had to be postponed for the time being. In his new letter Björndahl, stating that he considered the matter to be of great importance, asked for new orders. The King this time agreed and on 22 November ordered that a certain Lt. Westman (who had been present at Dünamünde) be instructed to cooperate with Biörndahl.
On 14 December Biörndahl wrote to Governor General Dahlbergh, reporting that the commission had met for the first time the previous day. They had then discovered that important witness Westman (now promoted to captain) had been arrested and Biörndahl requested that Dahlbergh permitted an interrogation.
On 16 January 1702 Biörndahl wrote again. Colonel Budberg had claimed that he had not received any instructions from Dahlbergh. If instructions had indeed been sent, the Commission wanted to have a look at them. They were also interested in seeing the explanation given to Dahlbergh by Budberg.
The inquest seems to have continued in February, but it's unclear to me how and when it ended.
LVVA, fond 7349, op. 1, vol. 149
LVVA, fond 7349, op. 1, vol. 294
LVVA, fond 7349, op. 1, vol. 316
Munthe, L., Kungl. Fortifikationens historia 3:2. - Stockholm, 1909-1911