Egyptian police have arrested a man suspected of planning last month's bomb attacks in the town of Sharm al-Sheikh, Interior Ministry sources say.
Police have questioned hundreds of people about the attacks
Hassan al-Arishi was detained at a house in the northern Sinai peninsula area, the sources said.
Mr Arishi had been using the identification papers of another man to cover his tracks, he added.
At least 64 people were killed when bombs exploded outside two hotels and a market in the Red Sea resort town.
Several groups have said they carried out the attacks, with at least one citing links to the al-Qaeda network.
Earlier this month, police killed another man they said was suspected of helping to plan the Sharm el-Sheikh attacks.
Police said Mohammed Suleiman Felaifil was killed in a shootout near Gebel Ataqa, near the northern town of Suez.
Three other men were reportedly arrested last week.
Reports suggest the other suspects had identified Mr al-Arishi.
On Sunday, the Egyptian state newspaper Al Ahram said investigators had uncovered nearly one metric ton of high explosives at a farm.