This matter is before the court on petitioners’ request to take a deposition of Jeanne Garrison, pursuant to Mass.R.Civ.P. 27. Petitioners seek to take this deposition to discover whether they have a claim against unknown third parties.
DISCUSSION
Mass.R.Civ.P. 27 authorizes pre-complaint depositions only for the purpose of perpetuating testimony. It does not sanction complaint-building discovery. James W. Smith and Hiller B. Zobel, Rules Practice, §27.2 at 238 (1975). If the petitioners do not know whether they can properly make a claim against the prospective defendant, they may not examine the witness to find out. Rule 27 is not a discovery rule and it is not the purpose of the rule to enable a would-be litigant to ascertain whether any facts exist upon which they may frame a complaint. Id., United States v. Local 14 International Union of Operating Engineers, 16 F.R. Serv.2d, 111, 112 (S.D.N.Y. 1972). Rule 27 applies only in limited situations; it does not seek to eliminate all the inconveniences and risks attendant *506upon delay in commencing an action. Smith and Zobel, supra, §27.2 at 238.
ORDER
For the reasons set forth herein, it is hereby ORDERED that the petition to take the deposition Of Jeanne Garrison be DENIED.