  We have studied the $\gamma d \to K^+ K^- n p$ reaction in which the LEPS
collaboration found a signal in the $K^+ n$ invariant mass for the claimed
$\Theta(1540)$ pentaquark peak. Our study reveal that the procedure used at
LEPS to reconstruct the $K^+n$ invariant mass generates an artificial strength
in the $\Theta(1540)$ region and that the LEPS collaboration underestimated the
background in that region, such that the signal observed for the $\Theta(1540)$
is compatible with a fluctuation of $2\sigma$ over the calculated background.
