The regional civil defense office said the five miners could have been trapped by huge boulders that would require a longer period to remove before their bodies could be recovered.
Such clearing operations would also require more personnel and a systematic procedure to bring out the debris inside the Sunshine portal of JB Management Corp.
JB Management, however, has begun clearing operations as early as last week.
The cave-in reportedly took place about 875 meters from the mouth of the Sunshine tunnel.
Toxic gas inside the tunnel delayed the retrieval of the remains of the trapped miners.
JB Management spokesman Bembot Española said volunteers from Lepanto Mines Corp. and Philex Mining Co. have returned to Baguio City after helping recover the bodies of at least 14 miners.
Civil defense officials identified the missing miners as Allan Poe Eraso, Raymundo Nisperos, Tirso Miguel, Ernie Francisco and Rey Hugo.
The Oct. 26 tragedy was the latest in a series of accidents, including landslides, at the gold-rush area where mining operations started in the early 1980s.
President Arroyo earlier ordered the creation of a regional rescue team specializing in mining disasters, particularly in identified mining sites in Compostela Valley.