"Reports of mediation between Saudi Arabia and Libya, and that this mediation achieved its objective, are not true," the official Saudi Press Agency (SPA) quoted a government source as saying.
Saudi Arabia has accused Libya of plotting to kill de facto ruler Crown Prince Abd Allah in 2003, after Abd Allah clashed with Libyan leader Muammar al-Qadhafi at an Arab summit. In December it recalled its ambassador from Tripoli and expelled Libya's envoy in Riyadh. Libya has denied the accusations.
Egyptian Foreign Minister Ahmad Abu al-Ghait earlier said Egypt had been mediating to resolve the row, and Cairo's efforts had "realised their goal and some breakthrough has been achieved in the position between Libya and Saudi".
The Saudi source said documents and investigations surrounding the "Libyan conspiracy" were a matter for the judiciary and results would be announced in due course.
Al-Ghait said Cairo had tried to
resolve the row
Interior Minister Prince Nayif bin Abd al-Aziz said on Sunday Saudi Arabia was close to concluding the investigation. Saudi security sources have said for months a trial of suspects involved in the alleged assassination plot could be imminent.
Washington has said that Tripoli has yet to answer US concerns about the alleged plot, which Washington said was an obstacle to dropping the North African state from the US list of state sponsors of terrorism and ending related sanctions.
In October, a US court sentenced prominent US Muslim activist Abd al-Rahman al-Amudi to 23 years in jail for illegal financial dealings with Libya and for his role in the alleged assassination plot.
Amudi said in court documents that he had contacted Saudi dissidents in London on behalf of Libyan officials to kill the crown prince.
In 2003, Prince Abd Allah and al-Qadhafi clashed at an Arab summit when the Libyan leader criticised Riyadh for hosting US forces before the Iraq war. Abd Allah walked out after angrily pointing at al-Qadhafi and questioning how he had come to power.