VATICAN CITY, Dec 14 (Reuters) - A corruption trial related to the Vatican"s purchase of a luxury building in London was adjourned for nearly six weeks on Tuesday, another long delay underscoring how it remains mired in its opening stages five months after it started. "We are still in an open construction site," an exasperated court president Giuseppe Pignatone said, reflecting impatience with the pace of proceedings, during a hearing that lasted only 10 minutes. The trial started in July with 10 defendants but four were later removed because of irregularities in the investigative phase. The court then ordered the prosecution to question the four again and either re-indict or drop charges. But the prosecution told the court on Tuesday that it had been able to question only one and hoped to be able to complete its work by Jan. 20. Cardinal Angelo Becciu, a once powerful Vatican official, has been the only defendant to attend every hearing. The prosecution on Tuesday also rejected assertions by the defence that not all the evidence was readily available for consultation, saying it had been deposited with the court. Pignatone adjourned the trial until Jan. 25 but said that he expected even that hearing to be "merely transitory and I hope for the last time," indicating that the trial would not get going in earnest until some time in February. Tuesday"s hearing was the fifth and shortest since the trial started on July 27 in a large office space in the Vatican Museums. The large number of defendants and lawyers made the regular Vatican courtroom too small to comply with COVID-19 restrictions. The trial revolves mostly around the purchase by the Vatican"s Secretariat of State of a commercial and residential building at 60 Sloane Avenue in London"s South Kensington, one of the wealthiest districts in the British capital. The prosecution has accused Becciu, other former Vatican officials or employees and outside middlemen involved in the deal of embezzlement, abuse of office, extortion and fraud, among other charges. They all have denied wrongdoing. The Secretariat of State sank more than 350 million euros into the London investment, according to Vatican media. The Vatican is now in the final stages of selling the building.