  We analyze the possibility to produce an intermediate Theta^+ via a
KN->\Theta+ formation process in gamma D-> pK^- X (X=nK^+,pK^0) reactions at
some specific kinematical conditions, in which a pK^- pair is knocked out in
the forward direction and its invariant mass is close to the mass of
Lambda(1520). The \Theta^+ signal may appear in the [\gamma D,pK^-] missing
mass distribution. The ratio of the signal (cross section at the \Theta^+ peak
position) to the smooth background processes varies from 0.7 to 2.5 depending
on the spin and parity of Theta+, and it decreases correspondingly if the pK^-
invariant mass is outside of the Lambda(1520)-resonance region. We analyze the
recent CLAS search for the Theta+ in the gamma D ->pK^-nK^+ reaction and show
that the conditions of this experiment greatly reduce the Theta+ formation
process making it difficult to extract a Theta+ peak from the data.
