diff --git a/backend/src/routes/immich.ts b/backend/src/routes/immich.ts
index 8e97219..9e11849 100644
--- a/backend/src/routes/immich.ts
+++ b/backend/src/routes/immich.ts
@@ -26,6 +26,7 @@ import { exceedsStorageQuota, getStorageRoot, prepareUploadedFile, requireAdminM
 // administrateurs, et ne parlent jamais à l'instance d'un autre arbre.
 
 const treeParamSchema = z.object({ id: z.string().min(1) })
+const treePersonParamsSchema = z.object({ id: z.string().min(1), personId: z.string().min(1) })
 
 const assignSchema = z.object({
   personId: z.string().min(1),
@@ -324,6 +325,33 @@ export const immichRoutes: FastifyPluginAsync = async (app) => {
     return reply.send(thumbnail)
   })
 
+  // Personne Immich déjà associée à une fiche, pour la marquer dans le sélecteur. Réservé aux
+  // administrateurs : l'identifiant n'entre jamais dans le graphe public.
+  app.get('/trees/:id/immich/links/:personId', async (request, reply) => {
+    if (!request.actor || request.actor.kind !== 'user') {
+      return reply.code(401).send({ error: 'authentication_required' })
+    }
+
+    const params = treePersonParamsSchema.safeParse(request.params)
+    if (!params.success) {
+      return reply.code(400).send({ error: 'invalid_params' })
+    }
+
+    if (!(await requireAdminMembership(app, request.actor.userId, params.data.id))) {
+      return reply.code(403).send({ error: 'forbidden' })
+    }
+
+    const person = await app.prisma.person.findFirst({
+      where: { id: params.data.personId, treeId: params.data.id, deletedAt: null },
+      select: { immichPersonId: true },
+    })
+    if (!person) {
+      return reply.code(404).send({ error: 'person_not_found' })
+    }
+
+    return reply.send({ immichPersonId: person.immichPersonId })
+  })
+
   app.post('/trees/:id/immich/assign', async (request, reply) => {
     if (!request.actor || request.actor.kind !== 'user') {
       return reply.code(401).send({ error: 'authentication_required' })
diff --git a/backend/test/immich.test.ts b/backend/test/immich.test.ts
index b4f5011..e999935 100644
--- a/backend/test/immich.test.ts
+++ b/backend/test/immich.test.ts
@@ -997,3 +997,37 @@ describe('Immich integration: durcissement des vignettes et des réponses', () =
     await app.close()
   })
 })
+
+describe('Immich integration: lien d’une fiche', () => {
+  it('tells an administrator which Immich person a file is linked to, and refuses others', async () => {
+    const app = createApp()
+    const token = await createUserToken(app)
+    prismaMock.person.findFirst.mockResolvedValue({ immichPersonId })
+
+    const linked = await app.inject({
+      method: 'GET',
+      url: '/trees/tree-1/immich/links/person-1',
+      headers: { authorization: `Bearer ${token}` },
+    })
+    expect(linked.statusCode).toBe(200)
+    expect(linked.json()).toEqual({ immichPersonId })
+
+    const memberToken = await createUserToken(app, 'user-member')
+    prismaMock.treeMembership.findUnique.mockResolvedValueOnce({ treeId: 'tree-1', userId: 'user-member', role: 'member', tree: { deletedAt: null } })
+    const member = await app.inject({
+      method: 'GET',
+      url: '/trees/tree-1/immich/links/person-1',
+      headers: { authorization: `Bearer ${memberToken}` },
+    })
+    expect(member.statusCode).toBe(403)
+
+    prismaMock.person.findFirst.mockResolvedValue(null)
+    const missing = await app.inject({
+      method: 'GET',
+      url: '/trees/tree-1/immich/links/person-unknown',
+      headers: { authorization: `Bearer ${token}` },
+    })
+    expect(missing.statusCode).toBe(404)
+    await app.close()
+  })
+})